Insurers counting on the law to usher in new customers say even short-lived quirks could sour Americans on participating — and that could scare away people who are on the fence about buying coverage — especially young, healthy people needed to make the law work, The Wall Street Journal has reported.

"Every glitch is a human being" who could become frustrated, said Tom Scully, a Medicare director during the George W. Bush administration.

Specifically, any difficulties in correcting glitches in the online registration system will impact the new law's implementation because that is how most young people will interact with Obamacare.

And word of mouth will spread fast that the online enrollment process is inconvenient, Michael Ramlet, CEO of the healthcare policy tipsheet Morning Consult, and a former expert at the think tank American Action Forum, told BuzzFeed.

"This is especially worrisome when it comes to the coveted young adults, who have the highest expectations for purchasing products online," Ramlet said.

"Starting tomorrow, tens of millions of Americans will be able to visit HealthCare.gov to shop for affordable healthcare coverage," Obama said. "So Americans who've lived for years in some cases with the fear that one illness could send them into bankruptcy, Americans who've been priced out of the market just because they've been sick once, they'll finally be able to afford coverage, quality coverage — many of them for the first time in their lives."

The president wants sick people to sign up for Obamacare — but he needs the young and healthy to sign up for the system to work.

Bill McInturff, a top pollster for Public Opinion Strategies, a firm used for market research by the insurance industry, told BuzzFeed there are early signs that the White House focus on healthcare is slowly gaining interest among younger people.

The number will have to rise by a lot, and a shutdown would make that job far tougher, McInturff said.

"... First we had Syria, and now we have, instead of Oct. 1 being kind of ... [a] press drumbeat about the exchanges coming online, it's about the government shutdown," he said.

Obamacare supporters have leveraged the president's support in the celebrity community to turn big stars into national spokespeople for the healthcare law, and young person-friendly outlets like Funny or Die have begun rolling out their campaigns to get the young, healthy, and uninsured to buy coverage under the exchanges.

Ramlet said he's looking to the holidays to be a big test: It might be parents who urge their kids to sign up for Obamacare that leads to a boost and helps Obamacare supporters reach their enrollment targets.

"For these less news-attentive folks, if there's a government shutdown they're not going to presume they're going to sign up for the exchange," McInturff said.

"For the advocates for Obamacare, this has been a disastrous September in terms of the kind of news environment that would have increased awareness and recognition."